Subsequent Treatment

If the alfalfa plants find the bacteria at hand,
they will begin to profit from them within the first month of their
lives. A large percentage of the plants may fail to obtain this aid in
land which has not previously grown alfalfa, and within a few months
they indicate the failure by their light color, while the plants
liberally supplied with nitrogen through bacteria become dark green.
Where there are no bacteria, the plants turn yellow and die.

There are diseases that attack alfalfa, causing the leaves to turn
yellow, and when they appear, the only known treatment of value is to
clip the plants with a mower without delay. The next growth may not
show any mark of the diseases.

When alfalfa is seeded in the spring on rich land, a hay crop may be
taken off the same season. If the plants do not make a strong growth,
they should be clipped, and the tops should be left as a mulch. The
clipping and all future harvestings are made when the stalks start buds
from their sides near the ground. This ordinarily occurs about the time
some flowers show, and is the warning that the old top should be cut
off, no matter how small and unprofitable for harvesting it may be. The
exception to this rule is found only in the fall. An August seeding may
make such growth in a warm and late autumn that flowering will occur,
and lateral buds start, but the growth should not be clipped unless
there remains time to secure a new growth large enough to afford winter
protection. This is likewise true of a late growth in an old alfalfa
field.

Owners of soils that are not well adapted to the alfalfa plant will
find top-dressing with manure helpful to alfalfa fields when made in
the fall. The severity of winters in a moist climate is responsible for
some failures. If the soil is not porous, heaving will occur. A
dressing of manure, given late in the fall, and preferably during the
first hard freeze, will prevent alternate thawings and freezings in
some degree. The manure should have been made from feed containing no
seeds of annual grasses or other weed pests.

Rolling in the spring does not serve to settle heaved alfalfa plants.
The tap-roots are long, and when they have been lifted by action of
frost, they cannot be driven back into place.

It is believed that the permanence of an alfalfa seeding may be
increased by the use of mineral fertilizers in the early spring. In the
case of one alfalfa field of fifteen years' standing in the east, the
fertilizers were applied immediately after the first hay crop of the
year was removed. Three hundred and fifty pounds of acid phosphate and
50 pounds of muriate of potash per acre is the mixture recommended.
When old alfalfa plants do not stand thickly enough on the ground,
grasses and other weeds come in readily. They can be kept under partial
control by use of a spring-tooth harrow, the points being made narrow
so that no ridging will occur. The harrow should be used immediately
after the harvest, and will not injure the alfalfa.

It does not pay to use alfalfa for pasturage in our eastern states
because the practice shortens the life of the seeding.

Alfalfa makes a seed crop in profitable amount only in our semi-arid
regions. No attempt to produce a seed crop in the east should be made.